Dehydrator for air brake systems



May 4, 1937. R. s. BEGG DEHYDRATOR FOR AIR BRAKE SYSTEMS Filed Jan. 22, 1936 ATTORNEY.

.V 25 thereto,

Patented May 4, 1937 ffnnnCn y A DEHYDRATOR FORQAIR4 BRAKE SYSTEMS letussell` Sr Begg, Detroit, Mich., assigner to The n I.

Midland Steel Products Company, Cleveland, Y

l y Ohio, a. corporation of-Oliio Application January 422,' 193s. serial Nn: 60.213?

invention relates to new and is drawn vintr) an. `air or vacuum brake system to preclude thepossibility of subsequent frosting ,and` condensation of `moist vapors in the system 1 and which would, if not extracted. be fatalto the `operation of the `system in freezing climate due to such freezing and frosting around the valves and other movable parts of the system rendering l-suchvalves or parts inoperative with consequent failure ofv the operation of the system.

Other objects andadvantages of the inven- 15 tion will become apparent during the course of the following description.

In the accompanying drawing forming a part of the application and wherein like numerals are employed to designate like parts throughout the 20 several views,"

I Fig. 1 isa side AelevationV of an internal combustionlengine for motor vehicles" illustrating a part of a compressed air brake mechanism associated therewith and the Fig.' 2 is an enlarged side elevation of the present preferred form of dehydrator with' parts thereof broken away'to illustrate certain details,l`

and Fig. 3 is an elevation of the strainers employed in the two ends -of the dehydrator.

While. the dehydrator hasfbeen illustrated in an air brake system, it will be understood that it is also useful in vacuum brake systems which in 35 actuality are low pressure air brake systems.

Referring now more particularly to the drawing for a more detailed explanation of the invention, the numeral 5 designates an internal `combustion engine having an exhaust gas mani- 0 fold 6 as associatedtherewith and the usual cooling fan 'I rotated by a belt8 from the crank or cam shaft. An air compressor 9 of the reciprocatory .type is mounted in any suitable manner to be ldriven by the crankshaft; the drive being here .45 shown as taken fromthebelt 8 by a pulley ,I0

fixed to theend of compressor crankshaft I. The` compressor of` course, Ipossesses the usual cylinder l2 4in `.which lis reciprocated the custom-'- y ary vpiston lfor compressing air.l

`50 "the cylinder isl as` usual 'provided withiriletV and l outlet ports andfvalves, theformer having an inverted U'shaped air intake pipe-I3 and the latter 'a pipeconnection I4 with a compressed air reser,` voir I5;A This reserVOir-isconncted inthe usual 55 way in a compressed air brake system -toan op- :L erat'ors control-'valve I 6 by a pipe I'I and the`` compressed air is directed from the reservoir to a brake cylinder I 8 for operating the brake shoes I9 by its valve I6 which also exhausts the air 60 upon operation of the valve in the opposite diinvention applied The head of f3, claims. lomos-1i useful irn` -provements in'l air dehydrators and an important 1 f object of the invention is to provide means for extracting moisture from atmospheric air which.

rectiOn. 'Ihe'positionof the 'inlet valve :of the air compressor sfcontolledby the usual governor mechanism'Zli connected, by a pipe 2I to the main reservoir I5'so `that when the desired air pressure is createdin the reservoirfthe inlet valve will beheld open'by the governorl 20 whereby the compressor is caused toidle so' far as the compression of air is' concerned byv the air being sucked into the inlet port on the downstroke of the compressor pistonl and thenl idly back out through the same upon the upstroke.

An air cleaner is usually associatedwith the inlet side of the compressor 9" to screen out'extraneous material from the atmospheric air sucked into the compressor to be subsequently compressed on the upstroke of the compressor piston and forced throughthe pipe III into the reservoir I5. However, these airfllters do not exclude moisture from the atmospheric air drawn into the system with the result that during the operation of the air brale system, moist vapors are condensed by the compression and expansion of the air and changing temperatures of pipes, tanks. etc., in service. After each `days run, busses: and trucksequipped with air brake systems must be drainedoi this water of "condensation` and 'during warm weather'is not a. source of much trouble. However, in colder weather the condensation is forced by air pressure through the system and into contact with lvalves and operative parts of the system and freezes around these movable parts, especially on the seats and bodies of valves sol as to prevent they proper performance thereof, frequently resulting in total failure of the system.

In order to overcome'these serious objections. a dehydrator is associated with the inlet pipe I3 of the compressor or the air inlets of a Avacuum system and in the present illustration it is shown composed of a cylindrical container 2| illustrated more clearly in Fig. 2. Theupper' end of this -container'detachably connects with the inlet pipe I3 and the lower end is `provided, with an air cleaner22 lled with crinklyhair or otherfllter- 'ing medium to exclude extraneous matter from only serve as baiiies vfor Vcausing aur'iiflorm iiow of vair through the cartridge orvjcontainer, but i e also prevent the accidental esc'apeof an absorption medium or material `25 er`1`closed inf the casing. The l`side"ofj thecasing zl'adjace'nt the air lter end is yprovidedf-with anA outlet nipple 26 e having a`sc'reen'21`over the'same and vthis nipple is closed by a plug 28 when the cartridgeor casing 2l is being used for dehydrating purposes.

The adsorption medium 25 found in actual co'l practice to be extraordinarily eective for excluding moist vapors from the commercial brake systems is a hard glassy material with the appearance of clear quartz sand and known as silica gel. This material is pure silicon dioxide and is chemically inert toward practically all substances. It is made by treating sodium silicate with an acid to form a colloidal solution which sets as a gelatinous mass and this when washed, purified and dried becomes a silica sponge which is granulated to a size of from 8 to 20 mesh. It has the property of adsorbing large quantities of vapors or liquids because its internal volume is approximately 50% of its total volume and will f adsorb or take up water vapor to the extent of 40% of its own weight while appearing perfectly dry and with no increase in volume. It is said that one cubic inch of this material has an internal surface of over one acre so that its adsorption qualities can well be appreciated. For the herein proposed use, the containers 2i are made to hold approximately five pounds of the material, amply sufficient to dehydrate all of the atnrospheric air drawn into a compressor such as used in truck or bus operation for one entire day. However, the herein proposed system employs the use of two such containers or cartridges for each installation so that they are interchangeable whereby when one is being used in the system, the other is being reactivated by the application of heat to the silicon dioxide which causes liberation of moisture and impurities to be again ready for use. v

g For the purpose of reactivating the interchangeable containers containing the saturated silicon dioxide, brackets 29 are associated with the exhaust manifold 6 of the internal combustion engine. This spare container is indicated by the letter S andthe brackets 29 are arranged so that this container is supported against the exhaust manifold in downwardly inclined relation with the plug 28 lowermost so that a drain pipe 30 may, if desired, be inserted in the opening from which the plug 28 has been removed. The air filter 22 may also be removed from the container being reactivated, if desired and the other end of the container which was connected to the inlet pipe I3, is connected to a pipe 3| which communicates with the compressed air pipe H through a manually operated valve 32 which can be manipulated to entirely cut off the branch 3| or to temporarily open this branch to a controlled flow of warm compressed air coming from the compressor I2 so that this air will flow through the silicon dioxide from one end of the container S to the other to reactivate the material while its companion cartridge or container 2| is in use absorbing moisture from the atmospheric air being sucked into the compressor. While the pipe i3 is shown as being threaded into one end of the container 2|, this connection may be of a quick detachable type so that the container can be rapidly slipped on and ofl of the end of the pipe, as in the'case of the connection between pipe 3| and the spare cartridge or cylinder being reactivated. This latter container S obviously receives heat from the exhaust manifold 6 as well as occasional blasts of warm air from pipe 3| whenever the valve 32 is opened to 'rapidlylvreactivate the silicon dioxide to be dehydrating medium therein becomes saturated with moisture. Of course, other absorption and dehydrating mediums than the one herein specincally described, may be employed and it is to be understood that various changes in the illustrated device may be made as will fall within the scope of the appended claims without departing from the essence of the invention. Other minerals such as calcium chloride may be used as the dehydrating or adsorption medium.

I claim:

l. 'I'he combination with a motor vehicle having brakes and an internal combustion engine having an exhaust gas manifold, an air compressor operated by the engine and having inlet and outlet valves, a reservoir, an expansion chamber to operate said brakes and a valve to control the passage of compressed air to said chamber, of a pair of interchangeable containers having a body of silicon dioxide therein, one of said containers being detachably connected to the inlet of said compressor and through which atmospheric air is drawn into the compressor to dehydrate the air and preclude the presence,

of moisture in the system while the other container is mounted to receive heat from the exhaust manifold to reactivate the silicon dioxide therein whereby the containers can be interchanged when the medium in the first named container approaches its saturation point.

2. The combination with a motor vehicle having brakes and an internal combustion engine having an exhaust gas manifold, an air compressor operated by the engine and having inlet and outlet ports, a reservoir connected by piping to the outlet port, an expansion chamber to operate said brakes and a valve to control the passage of compressed air to said chamber; of a pair o i' interchangeable containers having a body of silicon dioxide therein, one of said containers being detachably connected to the inlet port of said compressor and through which atmospheric air is drawn into the same to dehydrate the air and exclude the presence oi` moisture in the system, the other container being mounted to receive heat from the exhaust manifold and having vaived connection with the pipe from the outlet port to the reservoir whereby the silicon dioxide in said other container is reactivated whereby the containers can be interchanged when the medium in the first named container approached its. saturation point.

3. The combination with a vehicle provided with an internal combustion engine having an exhaust manifold, an air compressor operated by said engine, a brake system having a valve to control the flow of compressed air to the vehicle brakes, of a pair of interchangeable containers having an adsorption material therein, one of said containers being detachably connected in the brake system to dehydrate the air prior toits passage through the control valve to the brakes, the other container being bodily' disconnected from said brake system and mounted alongside said exhaust manifold to receive heat therefrom due to its proximity thereto to reactivate the adsorption medium therein, whereby the containers can be interchanged when the medium in the first named container approaches its saturation point.

RUSSELL S. BEGG. 

